If the Production Support Team can't resolve an issue, they pass it to me.
Recently, I was given the task to troubleshoot a linked server issue that had stumped other DBAs.
Both instances were SQL Server 2005. The DBAs tried multiple configurations but the linked server kept failing with either a timeout error or a network interface error.
I started from the beginning and tried to defined the linked server myself. Same results.
The one thing I think I did different is that I clicked on the For Help: link at the bottom of the error dialog.
After reading this entry, I took the recommended user action and pinged the target server via xp_cmdshell from the Query window on the originating server. No response.
Tada! It was a network connectivity issue and had nothing to do with how the DBA was configuring the linked server. I advised the DBA to call in a ticket for the network team.
The lesson here is try not to let your focus get too narrow when troubleshooting and use all the help that is offered.